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Search Results: 1 - 10 of 80886 matches for " Guifen Liu "
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Expression of HMGR in Lilu cattle tissues  [PDF]
Guifen Liu, Fachun Wan, Xiaomu Liu, Haijian Cheng, Xiuwen Tan, Enliang Song
Open Journal of Animal Sciences (OJAS) , 2012, DOI: 10.4236/ojas.2012.21007
Abstract: The 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR ) is an essential enzyme in cholesterol biosynthesis. To study the expression of HMGR in adipose and muscle tissues, and some performance indexes of four age stages, twelve Lilu cattle were selected. The results indicated that the Lilu beef cattle have good production and slaughter performance. HMGR mRNA expression level in adipose was higher than in muscle, but the trend in adipose was the same as in muscle. HMGR mRNA expression is difference in adipose and muscle tissues suggesting this gene is expressed in a tissue-dependent manner in cattle. Understanding the causes of variation in HMGR gene expression may provide crucial information about cholesterol biosynthesis in Lilu beef cattle.
DESIGN OF A PM-FO CUSING SYSTEM FOR THE GYROTRON
迴旋管永磁聚焦系统设计

Li Shengpei,Liu Guifen,
李声沛
,刘桂芬

电子与信息学报 , 1984,
Abstract: A new PM-focusing system with two regions of uniform magnetic field, suitable for gyrotron is proposed and studied with computer. In the calculation, a radial system made of Sm-Co magnets is used. The maximum magnetic energy-products (BH)max of the magnets are about 20MGOe. In order to adjust the magnitude of the magnetic field, some small coils are inserted into the two regions so that about five percent field change can be obtained.As a computed example a 40-50 kg Sm-Co PM-focusing system for an 8 mm band H02 mode gyromonotron operating at secondary harmonic of the cyclotron frequency is needed to obtain an intense magnetic field of 6500-7000 Gs. This is very atteractive for the development of 8 mm band gyrotrons and near-centimetre band ones. In the last part of the paper some problems such as the extension of the uniform region and increasing the efficiency of magnetic circuit are briefly discussed.
A Way to Set up Security Layer over Internet  [PDF]
Xiangyi Hu, Guifen Zhao, Guanning Xu
Journal of Computer and Communications (JCC) , 2015, DOI: 10.4236/jcc.2015.35022
Abstract:

A security architecture using secret key algorithm and vertical authentication mode is proposed. Establish security protocols in the chip of smart key at network client or mobile phone, and establish key exchange protocol in the chip of encryption cards at network key management center. A combined key real-time generation algorithm is used to solve the update and management problems. Online or offline authentication and documents encryption transmission protocols are adopted to achieve credible connection between users. Accordingly, set up security layer over Internet, which provides convenient encryption ability to each network user, and build credible and secure network system.

Building a Secure Mobile Payment Protocol in the Cloud  [PDF]
Liping Du, Guifen Zhao, Ying Li
Open Journal of Social Sciences (JSS) , 2016, DOI: 10.4236/jss.2016.47009
Abstract:

This paper is mainly to resolve the secure problems of mobile payment business which the remote payment is their main businesses. The identity authenticity of mobile payment user, the confidentiality and non repudiation of information transmitted in the mobile payment process are all the main secure problems. The secure mobile payment protocol is established base all the above secure problems’ solutions.

Roles of a sustained activation of NCED3 and the synergistic regulation of ABA biosynthesis and catabolism in ABA signal production in Arabidopsis
HuiBo Ren,YiJian Fan,ZhiHui Gao,KaiFa Wei,GuiFen Li,Jing Liu,Lin Chen,BingBing Li,JianFang Hu,WenSuo Jia
Chinese Science Bulletin , 2007, DOI: 10.1007/s11434-007-0072-9
Abstract: ABA, acting as a stress signal, plays crucial roles in plant resistance to water stress. Because ABA signal production is based on ABA biosynthesis, the regulation of NCED, a key enzyme in the ABA biosynthesis pathway, is normally thought of as the sole factor controlling ABA signal production. Here we demonstrate that ABA catabolism in combination with a synergistic regulation of ABA biosynthesis plays a crucial role in governing ABA signal production. Water stress induced a significant accumulation of ABA, which exhibited different patterns in detached and attached leaves. ABA catabolism followed a temporal trend of exponential decay for both basic and stress ABA, and there was little difference in the catabolic half-lives of basic ABA and stress ABA. Thus, the absolute rate of ABA catabolism, i.e. the amount of ABA catabolized per unit time, increases with increased ABA accumulation. From the dynamic processes of ABA biosynthesis and catabolism, it can be inferred that stress ABA accumulation may be governed by a synergistic regulation of all the steps in the ABA biosynthesis pathway. Moreover, to maintain an elevated level of stress ABA sustained activation of NCED3 should be required. This inference was supported by further findings that the genes encoding major enzymes in the ABA biosynthesis pathway, e.g. NCED3, AAO3 and ABA3 were all activated by water stress, and with ABA accumulation progressing, the expressions of NCED3, AAO3 and ABA3 remained activated. Data on ABA catabolism and gene expression jointly indicate that ABA signal production is controlled by a sustained activation of NCED3 and the synergistic regulation of ABA biosynthesis and catabolism.
Advance in enzymological remediation of polluted soils
污染土壤的酶学修复研究进展

ZHANG Lili,CHEN Lijun,LIU Guifen,WU Zhijie,
张丽莉
,陈利军,刘桂,武志杰

应用生态学报 , 2003,
Abstract: Soils enzymes play an important role in the remediation of polluted soils. The enzymological remediation of polluted soils has the characteristics of high specialization,wide applicability,and little sensitivity to the ambient factors. This paper reviewed the advantages of enzymological remediation of polluted soils,the methods and technologies of enzyme immobilization,and the removal mechanisms of pollutants by oxidoreductases. The sources and characteristics of the enzymes used to remediation were also introduced,and some suggestions about the research in the future were put forward.
Research advance in catalytic kinetics of soil hydrolase
土壤水解酶类催化动力学研究进展

ZHANG Yulan,CHEN Lijun,LIU Guifen,WU Zhijie,
张玉兰
,陈利军,刘桂芬,武志杰

应用生态学报 , 2003,
Abstract: Soil hydrolase is a group of soil enzymes that participated in many important biochemical reactions in soil and correlated with soil nutrient transformations. The catalytic kinetics of soil hydrolase can illuminate the characteristics of its catalytic processes,its substantial properties,and its response to environmental changes. This paper summarized the kinds of soil hydrolase and the main soil biochemical reactions they catalyzed,and summed up the research advances of their catalytic kinetics in soil. Some advices were proposed in understanding their action mechanism and in regulating their catalytic processes.
塔北西部早白垩世卡普沙良群沉积期 古隆起演化及其对沉积的控制作用
Evolution of Palaeo-Uplift and Its Controlling on Sedimentation of Kapushaliang Group of Early Cretaceous in Western Tabei Uplift

徐桂芬,林畅松,刘永福,孙 琦
Xu Guifen
, Lin Changsong, Liu Yongfu, Sun Qi

地球科学(中国地质大学学报) , 2016, DOI: 10.3799/dqkx.2016.051
Abstract: 古隆起是含油气盆地重要的构造单元,研究古隆起的分布及演化,并阐明其对沉积的控制作用,对于油气勘探具有重要 的研究意义.通过岩心、测井资料、地震资料和野外露头的综合研究,建立了塔北西部层序地层格架,卡普沙良群内部划分为4 个三级层序,在此基础上再造了卡普沙良群各层序发育时期古隆起的分布及其演化,SQ 1沉积时期古隆起呈近东西向展布, 横跨整个工区,由中部向东、西两侧加宽,隆起剥蚀面积为1946km2,SQ 2时期隆起范围缩小,中部隆起被淹没,东部残余2个 小的剥蚀区,西部剥蚀区范围较大,总面积约为1365km2,SQ3时期隆起范围进一步缩小,东部整体被淹没,西北部残余古隆 起面积为899km2,至SQ4时期古隆起消失.立足于岩心观察,结合岩矿组合、测井等资料,识别出辫状河三角洲、氧化型浅水 三角洲、滨浅湖滩坝和滨浅湖4种主要的沉积体系类型.最终充分运用地震、测井、岩心及分析化验等资料,采用盆地分析的思 想,综合研究了构造、古隆起、沉积古地理等要素,揭示了古隆起及源-汇体系的配置关系,研究区发育自古隆起向南北两侧 供源及南部远源供源两套物源体系,北部临近隆起剥蚀区的两侧发育短物源形成的辫状河三角洲沉积,随着隆起面积的减 小,辫状河三角洲分布范围逐渐减小,而南部长轴物源形成氧化型浅水三角洲沉积体系,呈现由SE向NW向逐步进积的趋 势,范围逐步扩大.古隆起的发育除为区域提供物源外,还有利于岩性圈闭和地层圈闭的发育,南部的滨浅湖滩坝砂体也具有 作为岩性圈闭的良好潜力
Palaeo-uplift is an important tectonic unit in the petroleum basin. The Research of palaeo-uplift distribution, its evolution and statement its influence on the development of sediment have important study significance for oil and gas exploration. Based on the comprehensive research of core, logging data, seismic data and outcrop, the sequence stratigraphy framework of Kapushaliang Group was established, which was divided into four third-order sequences internally. Then the palaeo-uplift distribution and its evolution in each sequence developmental stages of Kapushaliang Group were reconstructed. In SQ1 period, palaeo-uplift was EW trending, across the entire work area, widening from the middle to east and west, with an erosion-area of 1946km2. In SQ2 period, the palaeouplift area was decreased and submerged in the central uplift, 2 small eroded areas remained in the east and bigger eroded area in the west, with a total area of approximately 1365km2. In SQ3 period, the palaeouplift area was further decreased, the east was submerged overall and the northwest residual palaeouplift was 899km2, and the palaeo-uplift disappeared to SQ4. According to the core observation, combined with rock combination and logging data, four kinds of sedimentary system types are identified: the brainded river delta, oxidized shallow delta, beachandbar facies and shoreshallow lake. Finally the configuration relationship between palaeo-uplift and source-to-sink system is revealed, based on seismic data, logging, core and other analysis data, using the idea of basin analysis, and studying the factors of structure, palaeo-uplift, facies comprehensively. It is found that there are two source systems developed in the research area: the source from the palaeouplift to the north and south sides and source from distant southern source. The northern side near the erosion uplift area developed short provenance, which formed braided river delta
On the Betti Numbers of Shifted Complexes of Stable Simplicial Complexes
Zhongming Tang,Guifen Zhuang
Mathematics , 2004,
Abstract: Let $\Delta$ be a stable simplicial complex on $n$ vertexes. Over an arbitrary base field $K$, the symmetric algebraic shifted complex $\Delta^s$ of $\Delta$ is defined. It is proved that the Betti numbers of the Stanley-Reisner ideals in the polynomial ring $K[x_1,x_2,...,x_n]$ of the symmetric algebraic shifted, exterior algebraic shifted and combinatorial shifted complexes of $\Delta$ are equal.
Solvent Effects on Preparation of Pd-Based Catalysts: Influence on Properties of Palladium and Its Catalytic Activity for Benzyl Alcohol Oxidation  [PDF]
Feifei Wang, Guifen Hao, Yuming Guo, Xiaoming Ma, Lin Yang
Open Journal of Metal (OJMetal) , 2017, DOI: 10.4236/ojmetal.2017.74005
Abstract:
Solvent effects are important for the solution preparation of nanoscale metal materials, in which the sizes and properties of the nanomaterials are greatly influenced by the solvents. In this study, a series of Pd/XC-72 catalysts were synthesized by a facile solvothermal method in solvents with different numbers of hydroxyl groups, including ethanol, ethylene glycol, and glycerine. The as-prepared catalysts Pd/XC-72(EA), Pd/XC-72(EG) and Pd/XC-72(GI) were characterized by XRD, TEM, TGA, ICP-MS and multipoint nitrogen adsorption-desorption experiments. It was found that Pd/XC-72(GI) had the highest metallic dispersion and the smallest particle size (4.9 nm). Furthermore, Pd/XC-72(GI) exhibited the best catalytic performance for solvent-free selective oxidation of benzyl alcohol while the catalytic activities of Pd/XC-72 catalysts decreased in the order: Pd/XC-72(GI) > Pd/XC-72(EG) > Pd/XC-72(EA).
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